WATCH ABOVE: McKnight Boulevard was shut down for six hours after a high speed crash that left one person dead and two others in life-threatening condition. All three were ejected from the SUV that rolled over. Tracy Nagai reports.

“The Jeep began to rotate counterclockwise in the far right lane. The vehicle swerved and traveled a distance of 110 meters before entering the centre median. Once in the median the vehicle continued to travel a short distance before rolling across the eastbound lanes,” a Wednesday news release said.

All three people in the vehicle were ejected.

The male driver, believed to be in his 50s, was rushed to hospital in life-threatening condition. A female passenger sitting in the back seat of the vehicle, believed to be in her late teens or early twenties, was also transported to hospital in life-threatening condition.

A 17-year-old girl in the front passenger seat was taken to hospital where she later died.

Jan Ginther had been driving about three vehicles behind the SUV that crashed. She and her husband who have medical training jumped out to help.

“I sat with the one girl and my husband was sitting with the man. She was having a difficult time breathing. I did a jaw-thrust [maneuver] on her to try and help… we looked for ID so that we could have some names to go with them and so that we could talk to them,” Ginther said.

“I just held her and told her that she was loved and someone would be there soon.”

Emergency crews were called to McKnight Boulevard between 52 and 68th Streets Northeast for a serious collision Tuesday around 5 p.m.